Those would be enzymes I believe. They are the power house of the membrane and lower the amount of activation energy needed.
Arteries are blood vessels responsible for carrying oxygen-rich blood away from the heart to the body. Veins are blood vessels that carry blood low in oxygen from the body back to the heart for reoxygenation. Arteries and veins are two of the body's main type of blood vessels.
Solar power would, without doubt, be the most efficient type of power plant to build in this specific location. This is due to the fact that solar power produces no pollution in an environment. Also this type of alternative energy fits this communities resources due to the fact that the community receives primarily sun , a huge component in solar power, and little cloud coverage only increases the sun's power that much more. On the other hand, biomass needs things like wood, crops and alcohol fuels to burn in order to produce energy, some of which are not viable in this type of community because a place with little to no irrigation sources and an abundant amount of sunlight would be hard to produce any kind of natural aspect. Lastly, hydroelectric energy would not be a efficient of even viable choice because this community has no natural water available at hand to use for this alternative energy to function, and hydroelectric works primarily on a water storage.
The answer to this question would be: limbic system
Limbic system is part of the brain that responsible for emotion. One of this part is the olfactory bulb where the smells are processed. That is why a smell of something might make someone remember some memories that were related to the emotion.
In some organism, smells is important for survivability. Smelling a predator might cause the organism to feel fear and run away from them before they got close.
